A new approach to the evaluation of liver fibrosis has been proposed using PULSOMETRY. The objective is to evaluate the diagnostic performances of the FIBROSCAN technique, together with non-invasive techniques, and to determine how it is able to predict the histological fibrosis score, defined by the METAVIR score. This transversal study aims to compare the evaluation of hepatic fibrosis obtained by FIBROSCAN and histology (METAVIR score) in 2550 consecutive patients taken in charge for a liver biopsy. The results of the study will compare the respective performances of these techniques in the prediction of the METAVIR score, and help in the recommendation of the care of patients with viral hepatitis B and C; these methods will undergo a medico-economic study.